perf(desktop): lazy-load renderer routes and pause polling when hidden

Drop the eager Antd global import in favour of unplugin-vue-components
on-demand resolution, async route components, defineAsyncComponent for
the shell/login split, and a dynamic Modal import inside
showClientActionError. Pair that with a visibility-aware runtime poller
that stops the 15s snapshot refresh when the window is hidden and kicks
off an immediate refresh on re-show. Refresh DesktopShell nav with
inline icons and a calmer active/hover treatment, and land
ActionButton/DisclosurePanel/PaginationBar primitives for upcoming
views.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop-client/package.json

@@ -33,6 +33,7 @@
     "electron-builder": "^25.0.0",
     "electron-vite": "^2.0.0",
     "typescript": "^5.9.3",
+    "unplugin-vue-components": "^32.0.0",
     "vite": "^5.4.19",
     "vitest": "^2.0.0",
     "vue-tsc": "^3.2.6"